Dual-camera focusing method and apparatus, and terminal device

ABSTRACT

A dual-camera focusing method and apparatus, and a terminal device are provided. A dual camera includes a first camera and a second camera. A resolution of the first camera is higher than a resolution of the second camera. The method includes the following operations. The second camera is used for focusing. When the second camera is in focus, a second driving current value of a motor of the second camera is obtained. With the first camera and the second camera having a same in-focus distance, a first driving current value of a motor of the first camera is determined according to the second driving current value. The first driving current value is used to focus the first camera.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional patent application, which claimspriority to Chinese Application No. 201611079319.3, filed on Nov. 29,2016. The entire disclosure of the above application is incorporatedherein by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates to a technical field of photography, andmore specifically, the present disclosure relates to a dual-camerafocusing method and apparatus, and a terminal device.

BACKGROUND OF THE DISCLOSURE

With imaging technology of mobile terminals continually developing, moreand more mobile terminals use a dual camera for photography. This isbecause by combining different cameras to perform dual-camera imaging,photograph qualities or depth of field detection may be enhanced,thereby achieving better photography effects.

When cameras shoot a to-be-photographed object, the dual camera needs todetermine a focal length at which clear imaging can be accomplished, toshoot the to-be-photographed object at the focal length. However, in therelated art, a time period from an instance when the dual camera beginsfocusing to an instance when the focal length at which clear imaging canbe accomplished is determined is too long—that is, focusing speed isslower. In the related art, the slower focusing speed of the dual camerais disadvantageous to users performing snap shooting, and results indifficulties in capturing instant pictures.

DESCRIPTION OF THE DRAWINGS

Aspects and advantages of the present disclosure become apparent andeasy to be understood from the following description of embodiments inconjunction with the accompanying drawings.

FIG. 1 is a flowchart of a dual-camera focusing method in accordancewith an embodiment of the present disclosure.

FIG. 2 is a flowchart of a dual-camera focusing method in accordancewith another embodiment of the present disclosure.

FIG. 3 is a schematic diagram of a dual camera.

FIG. 4 is a schematic structural diagram of a dual-camera focusingapparatus in accordance with an embodiment of the present disclosure.

FIG. 5 is a schematic structural diagram of a dual-camera focusingapparatus in accordance with another embodiment of the presentdisclosure.

FIG. 6 is a schematic structural diagram of a terminal device inaccordance with an embodiment of the present disclosure.

FIG. 7 is a schematic structural diagram of a terminal device inaccordance with another embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present disclosure are described in detail below andexamples of the embodiments are illustrated in the accompanyingdrawings, wherein same or similar labels throughout the presentdisclosure represent corresponding same or similar elements orcorresponding elements having same or similar functions. The descriptionof the embodiments with reference to the accompanying drawings below isexemplary, aims at illustrating the present disclosure, and cannot beconsidered as limitations to the present disclosure.

In the following, a dual-camera focusing method and apparatus, and aterminal device, in accordance with embodiments of the presentdisclosure, are described below with reference to the accompanyingdrawings.

FIG. 1 is a flowchart of a dual-camera focusing method in accordancewith an embodiment of the present disclosure. The dual-camera focusingmethod uses a dual camera including a first camera and a second camera.As illustrated in FIG. 1, the method includes the following operations.

At block 101, the second camera is used for focusing.

At block 102, when the second camera is in focus, a second drivingcurrent value of a motor of the second camera is obtained.

Specifically, when the second camera is detected to be in-focus, adriving current value of the motor of the second camera for driving thesecond camera to perform focal length-adjusting movement to be at anin-focus distance is obtained. The driving current value is recorded asthe second driving current value.

At block 103, with the first camera and the second camera having thesame in-focus distance, a first driving current value of a motor of thefirst camera is determined according to the second driving currentvalue.

Specifically, a relationship between driving current values of the motorof the first camera and driving current values of the motor of thesecond camera is pre-obtained, so that when the first camera needsfocusing, with the first camera and the second camera having the samein-focus distance, the first driving current value corresponding to thesecond driving current value may be looked up.

Under ordinary situations, when a dual camera is in-focus, even thoughtwo cameras of the dual camera have the same in-focus distance, adifference in resolutions of the two cameras, and thereby a differencein sizes of the two cameras, cause the driving current values that themotors are based on when focusing the two cameras to have a certainratio relationship.

At block 104, the first driving current value is used to focus the firstcamera.

Further, after the first driving current value is used to focus thefirst camera, when the first camera is in focus, the first camera isused to take pictures.

In order to clearly describe the dual-camera focusing method asillustrated in FIG. 1, the present embodiment provides a possibleapplication scenario. The first camera of the dual camera isspecifically an ordinary camera and the second camera of the dual camerais specifically a dual-photodiode (dual-PD) sensor camera, a.k.a. a dualpixel camera, wherein a resolution of the dual-PD sensor camera is lowerthan a resolution of the ordinary camera. Therefore, the dual-PD sensorcamera can achieve faster focusing speed.

To facilitate understanding, a brief introduction of dual-PD sensorcameras is provided below. Each pixel of the dual-PD sensor cameras isformed by two units. The two units may serve detection points of phasedetection focusing, and may also be combined into one pixel for imaging,thereby significantly improving focusing performance during electronicview finding. Dual-PD complementary metal oxide semiconductor (CMOS)sensor cameras are relatively common dual-PD sensor cameras thatspecifically use CMOS for sensors. The earliest used dual-PD sensorcameras are single lens reflex cameras.

The dual-PD sensor cameras have a disadvantage—that is, the dual-PDsensor cameras output a huge amount of focusing data, two times a numberof sensor pixels. If the number of the sensor pixels is high, the amountof the focusing data would be large, and a data-processing capabilityrequirement for terminal device platforms needs to be increased.

A technical problem of the amount of the focusing data of the dual-PDsensor cameras being too large may be solved by using the dual camera.In the present embodiment, the ordinary camera serves as a main camera,and the dual-PD sensor camera, having the lower resolution, serves as anauxiliary camera. Because the dual-PD sensor camera has the lowerresolution, an amount of data processed by a terminal device platform isnot huge, and enough phase detection focusing information to be sharedwith the main camera can obtained, thereby increasing focusing speed ofthe main camera.

In the present embodiment, the second camera is used for focusing. Whenthe second camera is in focus, the second driving current value of themotor of the second camera is obtained. With the first camera and thesecond camera having the same in-focus distance, the first drivingcurrent value of the motor of the first camera is determined accordingto the second driving current value. The first driving current value isused to focus the first camera. Because the resolution of the secondcamera is lower, image processing speed of the second camera is faster,thereby enhancing focusing speed and solving the technical problem ofthe dual camera having slower focusing speed in the related art.

In order to more comprehensively describe methods of embodiments of thepresent disclosure, a method is described in detail below.

FIG. 2 is a flowchart of a dual-camera focusing method in accordancewith another embodiment of the present disclosure. The dual-camerafocusing method uses a dual camera including a first camera and a secondcamera. As illustrated in FIG. 2, the method includes:

At block 201, under a plurality of in-focus distances, correspondingdriving current values of a motor of the first camera and correspondingdriving current values of a motor of the second camera are pre-measured.

Specifically, under the in-focus distances, the corresponding drivingcurrent values of the motor of the first camera are pre-measured. Eachof the corresponding driving current values of the motor of the firstcamera is used to drive the first camera to perform focallength-adjusting movement to be at a first in-focus distance of thein-focus distances. Under the in-focus distances, the correspondingdriving current values of the motor of the second camera are measured.Each of the corresponding driving current values of the motor of thesecond camera is used to drive the second camera to perform focallength-adjusting movement to be at a second in-focus distance same asthe first in-focus distance. As illustrated in FIG. 3, the first cameraof the dual camera is specifically an ordinary camera 520 and the secondcamera of the dual camera is specifically a dual-PD sensor camera 540. Aresolution of the first camera is higher than a resolution of the secondcamera, and therefore a size of the first camera in FIG. 3 is largerthan a size of the second camera. Two cameras of the dual camera mayperform respective focusing, and the corresponding driving currentvalues of the motors can be determined under the in-focus distances. Theordinary camera 520 and the dual-PD sensor camera 540 are electricallyconnected to a camera connector 580 via camera connecting wires 560.

At block 202, a relationship of the driving current values of the motorof the first camera and the driving current values of the motor of thesecond camera is determined.

Specifically, according to the corresponding driving current values ofthe motor of the first camera and the corresponding driving currentvalues of the motor of the second camera measured under the in-focusdistances, the relationship between the driving current values of themotor of the first camera and the driving current values of the motor ofthe second camera is determined.

As a possible implementation, within an in-focus distance-drivingcurrent value coordinate space, a relationship curve of the in-focusdistances and the corresponding driving current values of the motor ofthe first camera is graphed, and a relationship curve of the in-focusdistances and the corresponding driving current values of the motor ofthe second camera is graphed.

At block 203, the second camera is used for focusing, and when thesecond camera is in focus, a second driving current value of the motorof the second camera is obtained.

At block 204, a first driving current value corresponding to the seconddriving current value is looked up.

Specifically, the looking up is performed based on the relationshipbetween the driving current values of the motor of the first camera andthe driving current values of the motor of the second camera, so as todetermine the first driving current value corresponding to the seconddriving current value.

At block 205, the first driving current value is used to focus the firstcamera.

At block 206, when the first camera is in focus, the first camera isused to take pictures.

In the present embodiment, the second camera is used for focusing. Whenthe second camera is in focus, the second driving current value of themotor of the second camera is obtained. With the first camera and thesecond camera having the same in-focus distance, the first drivingcurrent value of the motor of the first camera is determined accordingto the second driving current value. The first driving current value isused to focus the first camera. Because the resolution of the secondcamera is lower, image processing speed of the second camera is faster,thereby enhancing focusing speed and solving the technical problem ofthe dual camera having slower focusing speed in the related art.

In order to implement the foregoing embodiments, the present disclosureprovides a dual-camera focusing apparatus. The dual-camera focusingapparatus uses a dual camera including a first camera and a secondcamera. A resolution of the first camera is higher than a resolution ofthe second camera. FIG. 4 is a schematic structural diagram of adual-camera focusing apparatus in accordance with an embodiment of thepresent disclosure. As illustrated in FIG. 4, the dual-camera focusingapparatus includes a focusing module 41, an obtaining module 42, adetermining module 43, and a driving module 44.

The focusing module 41 is configured to use the second camera forfocusing.

The obtaining module 42 is configured to, when the second camera is infocus, obtain a second driving current value of a motor of the secondcamera.

The determining module 43 is configured to, with the first camera andthe second camera having a same in-focus distance, determine a firstdriving current value of a motor of the first camera according to thesecond driving current value.

The driving module 44 is configured to use the first driving currentvalue to focus the first camera.

It is to be noted that the foregoing description with respect to theembodiment of the dual-camera focusing method is applicable to thedual-camera focusing apparatus of the embodiment of the presentdisclosure. Principles of implementation are similar and the descriptionis omitted here.

In summary, in the present embodiment, the focusing module uses thesecond camera for focusing. When the second camera is in focus, theobtaining module obtains the second driving current value of the motorof the second camera. The determining module, with the first camera andthe second camera having the same in-focus distance, determines thefirst driving current value of the motor of the first camera accordingto the second driving current value. The driving module uses the firstdriving current value to focus the first camera. Because the resolutionof the second camera is lower, image processing speed of the secondcamera is faster, thereby enhancing focusing speed and solving thetechnical problem of the dual camera having slower focusing speed in therelated art.

Further, FIG. 5 is a schematic structural diagram of a dual-camerafocusing apparatus in accordance with another embodiment of the presentdisclosure. As illustrated in FIG. 5, the dual-camera focusingapparatus, with a basis as illustrated in FIG. 4, further includes apicture taking module 51.

The picture taking module 51 is configured to, when the first camera isin focus, use the first camera to take pictures.

Further, the dual-camera focusing apparatus further includes a measuringmodule 52 and a relationship determining module 53.

The measuring module 52 is configured to, under a plurality of in-focusdistances, pre-measure corresponding driving current values of the motorof the first camera, and measure corresponding driving current values ofthe motor of the second camera. Each of the corresponding drivingcurrent values of the motor of the first camera is used to drive thefirst camera to perform focal length-adjusting movement to be at a firstin-focus distance of the in-focus distances. Each of the correspondingdriving current values of the motor of the second camera is used todrive the second camera to perform focal length-adjusting movement to beat a second in-focus distance same as the first in-focus distance.

The relationship determining module 53 is configured to, according tothe corresponding driving current values of the motor of the firstcamera and the corresponding driving current values of the motor of thesecond camera measured under the in-focus distances, determine arelationship between the driving current values of the motor of thefirst camera and the driving current values of the motor of the secondcamera.

Specifically, the relationship determining module 53 is specificallyconfigured to, within an in-focus distance-driving current valuecoordinate space, graph a relationship curve of the in-focus distancesand the corresponding driving current values of the motor of the firstcamera, and graph a relationship curve of the in-focus distances and thecorresponding driving current values of the motor of the second camera.

Based on the above, the determining module 43 is specifically configuredto determine the first driving current value corresponding to the seconddriving current value. The determination is based on the relationshipbetween the driving current values of the motor of the first camera andthe driving current values of the motor of the second camera.

It is to be noted that the foregoing description with respect to theembodiment of the dual-camera focusing method is applicable to thedual-camera focusing apparatus of the embodiment of the presentdisclosure. Principles of implementation are similar and the descriptionis omitted here.

In summary, in the present embodiment, the focusing module uses thesecond camera for focusing. When the second camera is in focus, theobtaining module obtains the second driving current value of the motorof the second camera. The determining module, with the first camera andthe second camera having the same in-focus distance, determines thefirst driving current value of the motor of the first camera accordingto the second driving current value. The driving module uses the firstdriving current value to focus the first camera. Because the resolutionof the second camera is lower, image processing speed of the secondcamera is faster, thereby enhancing focusing speed and solving thetechnical problem of the dual camera having slower focusing speed in therelated art.

In order to implement the foregoing embodiments, the present disclosureprovides a terminal device. FIG. 6 is a schematic structural diagram ofa terminal device in accordance with an embodiment of the presentdisclosure. As illustrated in FIG. 6, the terminal device includes thedual-camera focusing apparatus 60 as illustrated in FIG. 4 or FIG. 5.

It is to be noted that the foregoing description with respect to theembodiments of the dual-camera focusing apparatuses is applicable to theterminal device of the embodiment of the present disclosure. Principlesof implementation are similar and the description is omitted here.

In summary, in the present embodiment, the focusing module uses thesecond camera for focusing. When the second camera is in focus, theobtaining module obtains the second driving current value of the motorof the second camera. The determining module, with the first camera andthe second camera having the same in-focus distance, determines thefirst driving current value of the motor of the first camera accordingto the second driving current value. The driving module uses the firstdriving current value to focus the first camera. Because the resolutionof the second camera is lower, image processing speed of the secondcamera is faster, thereby enhancing focusing speed and solving thetechnical problem of the dual camera having slower focusing speed in therelated art.

In order to implement the foregoing embodiments, the present disclosureprovides another terminal device. FIG. 7 is a schematic structuraldiagram of a terminal device in accordance with another embodiment ofthe present disclosure. As illustrated in FIG. 7, the terminal device1000 includes a housing 1100, and a memory 1111, a processor 1112, acamera module 1113, and motors 1114 located in the housing 1100.

The camera module 1113 includes a first camera and a second camera. Aresolution of the first camera is higher than a resolution of the secondcamera.

The memory 1111 stores executable program instructions. The processor1112 is coupled to the memory 1111 to access the executable programinstructions and when running the executable program instructions, theprocessor 1112 is configured to perform the following operations.

The second camera is used for focusing.

When the second camera is in focus, a second driving current value of amotor of the second camera is obtained.

With the first camera and the second camera having a same in-focusdistance, a first driving current value of a motor of the first camerais determined according to the second driving current value.

The first driving current value is used to focus the first camera.

Further, as a possible implementation, the second camera is a dual-PDsensor camera.

It is to be noted that the foregoing description with respect to theembodiments of the dual-camera focusing methods are applicable to theterminal device 1000 of the embodiment of the present disclosure.Principles of implementation are similar and the description is omittedhere.

In summary, in the present embodiment, the second camera having thelower resolution is used for focusing. According to the second drivingcurrent value of the motor of the second camera obtained when the secondcamera is in focus, the first driving current value of the motor of thefirst camera is determined. The first driving current value is used tofocus the first camera, realizing focusing of the first camera. Becausethe resolution of the second camera is lower, image processing speed ofthe second camera is faster, thereby enhancing focusing speed andsolving the technical problem of the dual camera having slower focusingspeed in the related art.

In the description of the present disclosure, terms such as “anembodiment”, “some embodiments”, “an example”, “a specific example”, and“some examples” referred to in the description mean at least oneembodiment or example of the present disclosure includes a specificfeature, structure, material or characteristic described in combinationwith an embodiment or example. In the present disclosure, anillustrative expression of the aforementioned terms does not need to befocused on the same embodiment or example. Further, the specificfeature, structure, material or characteristic described may beadequately combined in any of or a plurality of embodiments andexamples. In addition, in a situation where conflicts between each otherdo not exist, persons skilled in the art may combine and group differentembodiments and examples with features of different embodiments andexamples described in the present disclosure.

Although the embodiments of the present disclosure have been illustratedand described above, it is to be appreciated that the foregoingembodiments are illustrative and cannot be considered as limitations tothe present disclosure. Persons skilled in the art may change, modify,replace and vary the foregoing embodiments within the scope of thepresent disclosure.

What is claimed is:
 1. A dual-camera focusing method using a dual camerathat comprise a first camera and a second camera, wherein a resolutionof the first camera is higher than a resolution of the second camera,the method comprising: using the second camera for focusing; when thesecond camera is in focus, obtaining a second driving current value of amotor of the second camera; with the first camera and the second camerahaving a same in-focus distance, determining a first driving currentvalue of a motor of the first camera according to the second drivingcurrent value; and using the first driving current value to focus thefirst camera; wherein before the operation of determining the firstdriving current value of the motor of the first camera according to thesecond driving current value with the first camera and the second camerahaving the same in-focus distance, the method further comprises: under aplurality of in-focus distances, pre-measuring corresponding drivingcurrent values of the motor of the first camera, wherein each of thecorresponding driving current values of the motor of the first camera isused to drive the first camera to perform focal length-adjustingmovement to be at a first in-focus distance of the in-focus distances,and measuring corresponding driving current values of the motor of thesecond camera wherein each of the corresponding driving current valuesof the motor of the second camera is used to drive the second camera toperform focal length-adjusting movement to be at a second in-focusdistance same as the first in-focus distance; and within an in-focusdistance-driving current value coordinate space, graphing a relationshipcurve of the in-focus distances and the corresponding driving currentvalues of the motor of the first camera, and graphing a relationshipcurve of the in-focus distances and the corresponding driving currentvalues of the motor of the second camera.
 2. The dual-camera focusingmethod according to claim 1, wherein after the operation of using thefirst driving current value to focus the first camera, the methodfurther comprises: when the first camera is in focus, using the firstcamera to take pictures.
 3. The dual-camera focusing method according toclaim 1, wherein the operation of determining the first driving currentvalue of the motor of the first camera according to the second drivingcurrent value with the first camera and the second camera having thesame in-focus distance comprises: determine the first driving currentvalue corresponding to the second driving current value based on therelationship between the driving current values of the motor of thefirst camera and the driving current values of the motor of the secondcamera.
 4. The dual-camera focusing method according to claim 1, whereinthe second camera is a dual-photodiode (dual-PD) sensor camera.
 5. Thedual-camera focusing method according to claim 4, wherein the firstcamera is a camera other than a dual-PD sensor camera.
 6. A dual-camerafocusing method using a dual camera that comprise a first camera and asecond camera, wherein the second camera is a dual-photodiode (dual-PD)sensor camera, and the first camera is a camera other than a dual-PDsensor camera, the method comprising: using the second camera forfocusing; when the second camera is in focus, obtaining a second drivingcurrent value of a motor of the second camera; with the first camera andthe second camera having a same in-focus distance, determining a firstdriving current value of a motor of the first camera according to thesecond driving current value; and using the first driving current valueto focus the first camera; wherein before the operation of determiningthe first driving current value of the motor of the first cameraaccording to the second driving current value with the first camera andthe second camera having the same in-focus distance, the method furthercomprises: under a plurality of in-focus distances, pre-measuringcorresponding driving current values of the motor of the first camera,wherein each of the corresponding driving current values of the motor ofthe first camera is used to drive the first camera to perform focallength-adjusting movement to be at a first in-focus distance of thein-focus distances, and measuring corresponding driving current valuesof the motor of the second camera, wherein each of the correspondingdriving current values of the motor of the second camera is used todrive the second camera to perform focal length-adjusting movement to beat a second in-focus distance same as first in-focus distance; andwithin an in-focus distance-driving current value coordinate space,graphing a relationship curve of the in-focus distances and thecorresponding driving current values of the motor of the first camera,and graphing a relationship curve of the in-focus distances and thecorresponding driving current values of the motor of the second camera.7. The dual-camera focusing method according to claim 6, wherein aresolution of the first camera is higher than a resolution of the secondcamera.
 8. The dual-camera focusing method according to claim 7, whereinafter the operation of using the first driving current value to focusthe first camera, the method further comprises: when the first camera isin focus, using the first camera to take pictures.
 9. The dual-camerafocusing method according to claim 6, wherein the operation ofdetermining the first driving current value of the motor of the firstcamera according to the second driving current value with the firstcamera and the second camera having the same in-focus distancecomprises: determine the first driving current value corresponding tothe second driving current value based on the relationship between thedriving current values of the motor of the first camera and the drivingcurrent values of the motor of the second camera.
 10. A terminal device,comprising: a first camera; a second camera; wherein a resolution of thefirst camera is higher than a resolution of the second camera; a memorystoring executable program instructions; a processor coupled to thememory, wherein when running the executable program instructions, theprocessor is configured as a dual-camera focusing apparatus comprising:a focusing module configured to use the second camera for focusing; anobtaining module configured to, when the second camera is in focus,obtain a second driving current value of a motor of the second camera; adetermining module configured to, with the first camera and the secondcamera having a same in-focus distance, determine a first drivingcurrent value of a motor of the first camera according to the seconddriving current value; and a driving module configured to use the firstdriving current value to focus the first camera; wherein the dual-camerafocusing apparatus further includes: a measuring module configured to,under a plurality of in-focus distances, pre-measure correspondingdriving current values of the motor of the first camera, wherein each ofthe corresponding driving current values of the motor of the firstcamera is used to drive the first camera to perform focallength-adjusting movement to be at a first in-focus distance of thein-focus distances, and measure corresponding driving current values ofthe motor of the second camera, wherein each of the correspondingdriving current values of the motor of the second camera is used todrive the second camera to perform focal length-adjusting movement to beat a second in-focus distance same as the first in-focus distance; and arelationship determining module configured to, within an in-focusdistance-driving current value coordinate space, graph a relationshipcurve of the in-focus distances and the corresponding driving currentvalues of the motor of the first camera, and graph a relationship curveof the in-focus distances and the corresponding driving current valuesof the motor of the second camera.
 11. The terminal device according toclaim 10, wherein the dual-camera focusing apparatus further includes: apicture taking module configured to, when the first camera is in focus,use the first camera to take pictures.
 12. The terminal device accordingto claim 10, wherein the determining operation that the determiningmodule is configured to perform comprises: determining the first drivingcurrent value corresponding to the second driving current value based onthe relationship between the driving current values of the motor of thefirst camera and the driving current values of the motor of the secondcamera.
 13. The terminal device according to claim 10, wherein thesecond camera is a dual-photodiode (dual-PD) sensor camera.
 14. Theterminal device according to claim 13, wherein the first camera is acamera other than a dual-PD sensor camera.